We propose to study the biochemistry of the tissue responsible for aqueous humor formation, the ciliary processes. We will 1., seek evidence for a binding site for timolol distinct from the beta-adrenergic receptor which may explain how timolol lowers intraocular pressure, 2., characterize the ADP-ribosyl transferase of ciliary processes to explore the possibility that it regulates adenylate cyclase activity of this tissue, 3., evaluate the potential role of guanylate cyclase and cyclic-GMP in regulation of IOP and aqueous formation, 4., develop a technique for isolating and separating the epithelial cells of the ciliary processes. Characterization of the timolol binding site may lead to a better understanding of how this important drug lowers intraocular pressure. The other studies proposed may lead to a better understanding of the biochemical basis for the physiologic and pharmacologic properties of the ciliary processes. Separation of the ciliary epithelial cells will allow us to relate the unique biochemical, physiologic and pharmacologic properties of the epithelial cells to formation of aqueous by the processes.